feat(referencesImport): support named exports accessed via namespace …

…imports

* test(traverse): referencesImport
* feat(referencesImport): support named exports accessed via namespace imports
* feat(referencesImport): support `namespaceObj?.importName` and `namespaceObj["importName"]`
* refactor(referencesImport): simplify member expression computed branches
* test(referencesImport): aliased named import case
* fix(referencesImport): do not be fooled by import name "*"
  at least when detecting accessing a named import via a '*' import

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

packages/babel-traverse/src/path/introspection.ts

@@ -164,13 +164,30 @@ export function isStatementOrBlock(this: NodePath): boolean {
  */
 
 export function referencesImport(
-  this: NodePath<t.Identifier>,
+  this: NodePath<t.Expression>,
   moduleSource: string,
   importName: string,
 ): boolean {
-  if (!this.isReferencedIdentifier()) return false;
+  if (!this.isReferencedIdentifier()) {
+    if (
+      (this.isMemberExpression() || this.isOptionalMemberExpression()) &&
+      (this.node.computed
+        ? t.isStringLiteral(this.node.property, { value: importName })
+        : (this.node.property as t.Identifier).name === importName)
+    ) {
+      const object = (this as NodePath<
+        t.MemberExpression | t.OptionalMemberExpression
+      >).get("object");
+      return (
+        object.isReferencedIdentifier() &&
+        object.referencesImport(moduleSource, "*")
+      );
+    }
+
+    return false;
+  }
 
-  const binding = this.scope.getBinding(this.node.name);
+  const binding = this.scope.getBinding((this.node as t.Identifier).name);
   if (!binding || binding.kind !== "module") return false;
 
   const path = binding.path;

packages/babel-traverse/test/introspection.js

@@ -100,4 +100,108 @@ describe("path/introspection", function () {
       });
     });
   });
+
+  describe("referencesImport", function () {
+    it("accepts a default import", function () {
+      const program = getPath(`import dep from "source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "default")).toBe(true);
+    });
+    it("rejects a default import from the wrong module", function () {
+      const program = getPath(`import dep from "wrong-source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "default")).toBe(false);
+    });
+    it("rejects a named instead of default import", function () {
+      const program = getPath(`import { dep } from "source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "default")).toBe(false);
+    });
+
+    it("accepts a named import", function () {
+      const program = getPath(`import { dep } from "source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "dep")).toBe(true);
+    });
+    it("accepts an aliased named import", function () {
+      const program = getPath(`import { dep as alias } from "source"; alias;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "dep")).toBe(true);
+    });
+    it("accepts a named import via a namespace import member expression", function () {
+      const program = getPath(`import * as ns from "source"; ns.dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "dep")).toBe(true);
+    });
+    it("accepts a named import via a namespace import optional member expression", function () {
+      const program = getPath(`import * as ns from "source"; ns?.dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "dep")).toBe(true);
+    });
+    it("accepts a named import via a namespace import computed member expression", function () {
+      const program = getPath(`import * as ns from "source"; ns["😅"];`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "😅")).toBe(true);
+    });
+    it("rejects a named import from the wrong module", function () {
+      const program = getPath(`import { dep } from "wrong-source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "dep")).toBe(false);
+    });
+    it("rejects a default instead of named import", function () {
+      const program = getPath(`import dep from "source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "dep")).toBe(false);
+    });
+    it('rejects the "export called *" trick', function () {
+      const program = getPath(`import * as ns from "source"; ns["*"].nested;`, {
+        sourceType: "module",
+        plugins: ["moduleStringNames"],
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "nested")).toBe(false);
+    });
+
+    it("accepts a namespace import", function () {
+      const program = getPath(`import * as dep from "source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "*")).toBe(true);
+    });
+    it("rejects a namespace import from the wrong module", function () {
+      const program = getPath(`import * as dep from "wrong-source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "*")).toBe(false);
+    });
+    it("rejects a default instead of a namespace import", () => {
+      const program = getPath(`import dep from "source"; dep;`, {
+        sourceType: "module",
+      });
+      const reference = program.get("body.1.expression");
+      expect(reference.referencesImport("source", "*")).toBe(false);
+    });
+  });
 });